Method and apparatus for changing speed ratios in laundry machines



May 30, 1967 A. D. ISHOY ETAL 3,322,278

METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES Filed June 2), 1964 6 Sheets-Sheet 1 IN V F N TOP LPQymiM QZ z M VZVWFFTORNEYS A. D. ISHOY ETAL METHOD AND APPARATUS FOR CHANGING SPEED May 30, 1967 RATIOS IN LAUNDRY MACHINES I Filed June 9, 1964 6 Sheets-Shem 2 INVENTOR.

May 30, 1967 Filed June 9, 1964 A. D. ISHOY ETAL METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES 6 Sheets-Sheet A TT )RNE YS y 30, 1967 A. D. ISHOY ETAL 3,322,278

METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES Filed June 9, 1964 6 Sheets-Sheet 4 I NVE NTOR.

y 30, 1967 D. ISHOY ETAL 3,322,278

A. METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES Filed June 9, 1964 6 Sheets-Sheet T May 38, W67 A. D. ISHOY ETAL METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES Filed'June 9, 1964 6 Sheets-Sheet WQQQ WW m l @ayma United States Patent 3,322,278 METHOD AND APPARATUS FOR CHANGING SPEED RATIOS IN LAUNDRY MACHINES Albert D. Ishoy, Hartford, and Raymond M. Goodman,

Benton Harbor, Mich, assignors to Whirlpool Corporation, Benton Harbor, Mich, a corporation of Delaware Filed June 9, H64, Ser. No. 373,776 9 Claims. (Cl. 210-78) The present invention relates 'broadly to home appliances, and is more particularly concerned with an acceleration control system featuring therein a'variable speed transmission incorporating fluid pressure actuated friction clutch means to increase the speed ratio of the transmission incrementally in response to deflections or vibrations caused by rotation of unbalanced loads in a substantially horizontal drum or receptacle.

The acceleration control system and variable speed transmission of the present invention find important applications in association with laundry appliances and particularly with domestic combination washer-dryer automatic washing machines, and an exemplary embodiment will be described in that environment. However, as the description proceeds it will be readily apparent that the dis closed control system and transmission may he of general utility.

The acceleration control system of this invention also finds exceptional utility when used in combination with a balance system for correcting or rendering ineffective unbalanced forces in the drum of the washing machine at higher spin and extracting speeds due to unbalanced loads therein. The present invention includes a variable speed transmission interconnecting the drum of the washing machine with a drive motor, and the transmission has a low speed ratio for tumbling fabrics at a lower washing speed, an intermediate speed ratio for rotating the drum at a low speed, and a high speed ratio to permit drum rotation at higher extracting speeds for extracting fluids from the fabrics in the drum. As part of the transmission of this invention, there is included a pneumatic friction clutch effective to change or shift the transmission from its low to intermediate or high speed ratios. The pneumatic friction clutch is connected to a solenoid operated air valve which in turn is connected to sensing means responsive to movements of the drum due to rotation of unbalanced loads therein at the intermediate and high speed ratios, so that the friction clutch slips when an unbalanced load is sensed to maintain the speed ratio of the transmission at a value between the low and high speed ratios, thereby limiting rotation of the drum to a safe optimum speed above the tumble speed.

In this manner, the drum speed is maintained during the balancing operation at approximately the speed that produced suflicient centrifugal force to produce the necessary deflection to initiate drum balancing and bleed off the air pressure on the pneumatic clutch. As the offbalance load is corrected or counter-balanced, the deflection decreases with the result that the pneumatic clutch again receives uninterrupted full pressure, and acceleration continues. Additionally, novel apparatus and a method are provided to disengage the clutch when the transmission is shifted from intermediate to high speed, thus providing a no-load condition on the transmission when the shifting is accomplished and subsequently reestablishing the clutch pressure gradually.

It is an object of the present invention to provide a method for gradually accelerating drum speed of an automatic washing machine having a multiple speed transmission and a pneumatic friction clutch, whereby the clutch is disengaged when the transmission is shifted from a low spinning speed ratio to a higher spinning speed ratio.

Another object of the present invention is to provide improved acceleration control apparatus for a rotating receptacle.

Another object of the present invention is to provide an acceleration control system whereby the speed of a rotating receptacle is accelerated from a lower to a higher speed gradually or incrementally.

Still another object of the present invention lies in the provision of a system embodying variable speed, geartype transmision means, a sequential controller and a pressurized fluid-operated clutch means adapted to provide a programmed shifting from a low speed ratio to a high speed ratio without a load on the transmission by sequentially disengaging the clutch before changing speed ratios and subsequently re-establishing the clutch pressure in a gradual manner.

Yet another object of the present invention is to provide an acceleration control system incorporating a gear-type variable speed transmission and a fluid operated clutch means associated therewith, whereby the clutch is dis engaged while the transmission is shifted from a lower to a higher speed ratio, the clutch then being re-engaged gradually to allow for certain slippage thereof, thereby providing gradual increase in speed of the output shaft of the transmission.

Another object of the present invention is to provide an automatic washing machine with an acceleration control system whereby the drum speed of the machine can be increased from a lower spinning speed to a higher eX- tracting speed gradually.

Many other features, advantages and additional objects of the present invention will become manifest from the detailed description which follows wherein an exemplary structural embodiment of an acceleration control system incorporating the principles of the present invention is shown by way of illustration. It is believed that description of the structural characteristics of the present invention will also make clear the method steps by means of which the inventive concepts of the present invention can be performed.

On the drawings:

FIGURE 1 is a side elevational view of a laundry machine incorporating the principles of the present invention, but with portions of the outer cabinet removed;

FIGURE 2 is a fragmentary front elevational view of the machine of FIGURE 1 with the outer cabinet removed and with parts removed and other parts broken away and including a layout of a sensing mechanism which may be employed for limiting transmission speed due to unbalance of the machine;

FIGURE 3 is a more or less diagrammatic view, with portions thereof taken in section, showing an acceleration control system embodying novel concepts of this invention;

FIGURE 4 is a fragmentary top plan view of a variable speed transmission constructed in accordance with the principles of this invention;

FIGURE 5 is a sectional view of a transmission means of this invention;

FIGURE 6 is a detailed sectional view of compressor means which may be employed to supply air pressure to the pneumatic clutch of the transmission means of FIG- URES 4 and 5;

FIGURE 7 is a fragmentary detailed sectional view of the relief valve of the compressor of FIGURE 6;

FIGURE 8 is a schematic wiring diagram illustrating electrical circuitry of the present invention;

FIGURE 9 is a diagram illustrating periods of energization of electrical apparatus of FIGURE 8;

FIGURE 10 is a graph illustrating variations in fluid pressure during operation of the present invention; and

FIGURE 11 is a graph illustrating variations in drum 3 speed of a washing machine incorporating the principles of the present invention.

As shown on the drawings:

A-s appears in FIGURES 1 and 2, a domestic laundry appliance in the form of a combination washer-dryer is designated generally by numeral 10, and comprises an 'outer cabinet 11 having a suitable door controlled opening therein for selective access to a treatment zone.

Within the outer cabinet 11 is rigid 'ba-se structure shown generally at 13, comprising a channel member 13a to which is fixedly secured a plate 14. The base structure or frame 13 includes front legs 15 bolted to the channel member 13a, and a single rear leg 16 bolted to member 17 which is welded or otherwise secured to rear wall 18a of a generally imperforate outer casing 18 (FIGURES 1 and 2).

The casing 18 is connected to and supported on the base frame 13 by a front support plate member 19 which is integrated with a front wall 18b of the casing 18 by welding or similar techniques. The plate member 19 is further securely fastened to the plate member 14 of the base frame 13, by fasteners such as bolt means 20'.

The rear wall 18a of the casing 18 cooperates with a pair of support spiders 21 and 22 connected in firm assembly therewith to rigidly mount a bearing assembly generally designated at 23 in which is journalled shaft means 36 connected for corotation with a perforate drum or cylinder 24 rotatable within the casing 18.

It is to be noted that the connections provided by the parts 14 and 19 between the base frame 13 and casing 18 are rigid connections, however, there is suflicient yieldability in such connections so that some very small move ment of the casing 18 relative to the base frame 13 may occur. The connections afforded by the connection of the plate members 14 and 19 to the channel member 13a and the connection of the parts 17 to the casing 18 are sufficiently rigid to confine the casing 18 for oscillatory movements about axes positioned parallel to and located below the horizontal rotational axis of the drum 24 prescribed by the connecting shaft means. In the machine exemplified in the drawings, such allowable arcuate movement is approximately 0.010 inch on each side of its normal centered position as measured from an approximate 16 inch lever arm from the base frame 13.

The machine 10 is equipped with an electric drive motor 25 mounted on the casing 18 and having a power takeoff shaft drivingly connected with a transmission shown generally at 26, mounted on the casing 18, and having a pair of generally parallel output shafts 26a and 26b (FIGURE mounting pulleys 27 and 28. The pulley 27 engages a pulley belt 29 which connects with blower means and pump means. The pulley 28, on the other hand, engages a pulley belt 30 driving wheel 31 to rotate the drum 24 at one of three variable speeds provided by the transmission means 26.

It will be understood that the machine has a sequential control means shown generally at 33 which is pre-settable by the operator and which is associated with the usual electrical circuitry with all of the operating components of the machine, including the electric drive m0- tor 25, transmission means 26, the various valve means employed, and particularly solenoid valve means and switch means to be later described in detail which is in control of the pneumatic clutch means forming a part of the transmission 26. The sequential control means 33 by the various electrical connections actuates the machine to a program consisting of washing, rinsing, extracting and drying periods.

The acceleration control system of the present invention is effective to sense oscillatory movement or vibration of the drum 24 due to an unbalanced load when the drum is accelerating to intermediate or high speeds, and to maintain the speed of the drum at such speed as cause the movement until a balancing system has corrected the unbalanced forces on the drum, at which time the acceleration control system acts to continue acceleration control system acts to continue acceleration of the drum to its predetermined speed or until vibration of the drum again becomes excessive, whereupon speed of the drum is maintained until the unbalanced forces are corrected. The acceleration control system as as described briefly herein is described in more detail in copending application Ser. No. 72,449, filed Nov. 29, 1960, by R. A. Brenner et al. and assigned to the assignee of the present application and now US Patent No. 3,148,144.

In order to provide a stationary reference for the easing 18 relative to the base frame 13, there is utilized an A-shaped sub-frame 37 (FIGURE 2) including an oblique leg 38 fastened in firm assembly with the base frame 13 at 39, as well as a vertical leg 40 secured to the base frame at 41. A bracket 42 is fixedly fastened to the casing 18 by suitable fastening means such as bolts 43, and is provided with means which cooperate with a double acting bleed off or relief valve, to be described hereinafter, mounted on the stationary A frame 37, for sensing oscillatory movement of the casing 18 relative to the A- shaped sub-frame 37.

As the gear-type transmission 26 is shifted from intermediate or spin speed to high or extraction speed, the power output from the transmission to the drum is momentarily interrupted during the shifting of the gears, and the power output of the drum is then re-applied gradually and in increments to provide a smooth or soft-shift transition from intermediate to high speed, thereby avoiding jolting or surging of the drum and the associated speed-changing members.

In accordance with this invention a double acting bleedoff or relief valve is mounted on the stationary A-frame structure 37 and is actuated in response to vibrations caused by rotation of an unbalanced load in the drum 24. The valve connects with an outlet port of a solenoid operated air valve means and is constructed to provide a pressure bleed-off line between an air compressor and the pneumatic clutch means in the transmission 26.

An air compressor mounted on the transmission means driven thereby communicates air to an inlet port in the solenoid valve means, and the solenoid is energized to cause the drum 24 to accelerate from low to intermediate to high speed by pressurizing a chamber within the solenoid valve means leading to the pneumatic clutch. A high speed spin solenoid 128 is also energized to cause the machine to go into the high spin speed portion of the cycle, and in accordance with the principles of the present invention the pneumatic clutch is momentarily disengaged during this transition from intermediate to high speed to provide a smooth or soft-shift of the transmission 26.

When an off-balance load is accelerated and produces a deflection, the bleed-off valve on the stationary A-frame 37 is intermittently opened to reduce the pressure in the solenoid valve chamber. This has the effect of reducing the supply pressure to the pneumatic clutch in the transmission means, causing the clutch to intermittently slip to prevent increased drum acceleration. During this period of clutch slippage, the off-balance load may be counterbalanced by the balance system. However, and as will be pointed out in detail hereinafter, the drum rotative speed is not reduced, but is maintained at essentially the speed which caused the casing deflections so that there is no interference with accomplishment of the proper balancing function.

The acceleration control system of this invention is more or less diagrammatically illustrated in FIGURE 3, and it may be seen therefrom that the drive motor 25 connects with a transmission means 26 having output shafts 26a and 26b mounting pulleys 27 and 28 constituting the output of FIGURE 3. As shown in FIGURE 3 conduit means 46 is in communication with the transmission means with an outlet port 47 of solenoid operated air valve means generally designated by the numeral 48. A

compressor 49 connects through its outlet port with conduit means 50 leading to an inlet port 51 of the solenoid valve means 48. The solenoid valve means is further provided with a second outlet port 52 which communicates through conduit means 53 with a double acting bleed-off or relief valve means designated generally by the numeral 54.

The solenoid valve means 48 is provided with a body portion 56 having at one thereof a plurality of threaded openings 57a, 57b, and 57c receiving coupling members 58a, 58b and 58c, respectively, which are internally bored to provide the outlet ports 52, inlet port 51 and outlet port 47.

The body portion 56 of the solenoid valve means 48 is shaped interiorly to provide a chamber 59 communicating with the ports 52, 51 and 47 through reduced diameter passages 52a, 51a and 47a. The chamber 59 com-municates with a chamber 60 through a central aperture 61a in a rigid diaphragm member 61, which is further provided with vent passages 61b leading through vent passages 5611 in the body portion 56 to atmosphere.

The central aperture 61a in the rigid diaphragm member 61 receives a generally T-shaped flat surfaced valve member 62 positioned for contact with a solenoid armature 63 when solenoid 64 is de-energized. It may be noted from FIGURE 3 that the solenoid armature 63 has a central axial passage 63a and bottoming at one end thereof is spring means 66 which also bottoms against a fixed plug member 67 having a passage 67a therein. The plug member 67 may be secured in any suitable manner to a solenoid housing 68, and if desired, seal means 69 may be located between the solenoid armature 63 and plug member 67.

The energization of the solenoid 64 of the solenoid operated valve means 48 controls the shifting of the three speed transmission 26 from low to intermediate speed. When the solenoid is de-energized, the spring loaded solenoid armature 63 (shown energized in FIGURE 3) assumes its upper-most position which forces the valve member 62 against the surface 59a, which in turn permits cavity or chamber 59 to be vented to atmosphere through the vents or passages 61a, 61b and 56a in the rigid diaphragm 61 and body portion 56, respectively. This prevents the increased air pressure from the compressor 49 from reaching the pneumatically operated clutch in the transmission 26. In addition, this action blocks the inlet passage 51a to the chamber 59, and the compressor 49 can thereby build up pressure until its relief valve means bleeds-off the excess pressure.

When it is desired to shift the transmission 26 from low to intermediate speeds, the solenoid 64 is energized through suitable electrical circuitry which is connected to the presettable timer means 33. V/hen the solenoid is energized the armature 63 thereof withdraws against the pressure spring means 66 to essentially the position of FIGURE 3. The air pressure from the inlet port Sll, coupled with gravitational forces, moves the valve member 62 to a seating position upon surfaces 610 of the rigid diaphragm member 61. This blocks communication between the valve chambers 59 and 6t and pressurizes both of the valve outlets 47 and 52. The outlet port 47 leads to the pneumatic clutch and the transmission 26, causing this clutch to operate the transmission through suitable gear means and spring clutch means to shift to intermediate speed. The outlet 52 of the valve means 48 connects to the bleed-off valve 54, and as an off-balance load is accelerated and produces a deflection, the bleed-off valve is intermittently opened to cause a reduction of the air pressure in the chamber 59. The reduced air pressure acting upon the pneumatic clutch causes clutch slippage and a termination of increased drum acceleration, until the off-balance load is counter-balanced.

When it is desired to shift the transmission 26 from intermediate to high speed, the solenoid coil 64 is deener gized through said electrical circuitry to interrupt the air supply and thereby relieving the pressure from the pneumatic clutch of the transmission 26 until, through suitable gear means and clutch means, the transmission is shifted into high speed. Subsequently, the solenoid 64 is again energized to again provide an air supply to pressurize the pneumatic clutch means in the transmission, and as the pressure is resumed slippage in the pneumatic clutch means decreases, the power output of the transmission is gradually increased to transfer more power to the high speed gear train, providing a smooth or softshift from intermediate to the high speed ratio. If the drum 24 is in balance at the time of shifting, the drum will be immediately accelerated to the maximum high speed, but if an off balance condition exists, bleed-01f valve 54 will relieve the pressure from the clutch until proper balance can be restored as described in more detail hereinafter.

As appears in FIGURES 2 and 3, the double acting relief valve means is constructed to provide a body portion 70 having outlet portions 71 and. 72 threadedly receiving collar portions 73 in each of which travels valve core stems 74 and 74a. The valve body portion 70 is mounted on support means 76 (of FIGURE 2) carried by a plate portion 77 welded or otherwise firmly secured to the brace members 38 and 40 of the A-frarne 37. The angular position of the support means 76 relative to the plate member 77 may be adjusted by screw means 78 and 79. The body portion 70 of the air valve means 54 may be adjusted linearly with respect to support means 76 by means of a screw 79a.

The plate member 77 mounts a pivot pin 80 receiving the adjustable support means 76, as well as a yoke member 81 having arm portions 81a and 81b relatively closely spaced from the valve core stems 74 and 74a.

As appears in FIGURE 2, the bracket 42 rigidly mounts a lever member 82 having a claw portion 82a engageable with the yoke member 81 and an end portion 82!) connected by a spring 83 to said yoke member. When the support means 76 is properly adjusted in a static condition, the yoke arm portions 81a and 8112 are spaced at substantially equal distances from the valve core stems 74 and 74a. When the casing and drum assembly starts to oscillate about its center of oscillation due to the acceleration of an off-balance load, the yoke member 81 will also oscillate about the pivot pin 80 driven by lever member 82. With the support means properly adjusted as stated and assuming deflection of the casing and drum assembly, the yoke arm portions 81a and 81b will depress the valve core stems 74 and 74a as the casing 18 oscillates with respect to the A-frarne 37 to bleed-off air pressure from the pneumatic clutch, terminating increased acceler ation, although maintaining the drum speed relatively constant for effecting balancing with the balancing system.

Referring now to FIGURES 4 and 5, the transmission means 26 is provided with a housing 86 comprising a pair of body portions 87 and 88 secured one to the other by fastening means 89. The body portions 87 and 88 are formed at opposite ends with apertured embossments 90ad receiving bearing means 91a-d in which are journalled the shaft means 26a and 26b. The bearing means 9 1ad may be of the needle type as shown, and desirably the shaft means 26a and 26b mount thrust bearings 92 and 93.

The shaft means 26a and 2612 are supported within the transmission housing 86 in the manner indicated in parallel alignment, and carried by the output shaft 26a or machined integral thereon is a low or tumble speed drive pinion gear 94 in meshing relation with a low speed driven gear 96 freely rotatable upon the output shaft 26b. The pinion 94 is constantly in meshing engagement with the driven gear 96 to drive said gear at constant speed. The driven gear 96 has formed thereon an eccentric cam surface 97 against which bears cam follower means 98 of the compressor 49, said follower means to be described in a greater detail in connection with FIGURE 6. In this manner, the compressor 49 is also driven in a constant speed.

One face of the low or tumble speed driven gear 96 is formed with diametral slots or grooves 99 which mate with diametral raised ribs or protuberances 100 provided on one face of an internally threaded clutch drive plate 101 mounted on an externally threaded clutch plate mounting hub 102 fixedly secured to the output shaft 2612 as at 103. The periphery of the clutch drive plate 101 is grooved as at 10111 to frictionally mount a resilient spring wire loop member 104 one end of which is secured to pin means 106 secured to and extending axially through the driven gear 96.

The gear 96, clutch members 101 and 101 and spring member 104 function in the following manner. When the drive motor 25 flexibly coupled to the shaft means 26a is started and with air valve solenoid 64 de-energized, the low speed driven gear 96 and clutch plate 101 are normally slightly spaced with their engaging faces 99 and 100 separated. As the tumble speed driven gear 96 is driven from the tumble speed drive gear 94, the gear 96 initially overrides the stationary drum drive output shaft 26b. The spring member 104 wrapping the clutch plate 101 rotates with the gear means 96, and due largely to the friction between the clutch plate 101 and spring member 104, the clutch plate 101 rotates therewith and threads itself to the left in FIGURE upon the threaded hub 102 which is keyed or otherwise secured to the shaft 261). The threading action continues until the clutch plate means 101 is in clutching engagement by means of the slots 99 and protuberances 100 with the low speed driven gear 96, and at this time the output shaft 26b is driven at a speed that drives the drum or cylinder 24 at tumble or low speed through the externally threaded keyed hub 102.

To provide an intermediate speed (low spin speed rotation) for the drum or cylinder 24, the transmission 26 is equipped with an intermediate speed drive gear 107 fixed at 108 to a clutch housing 109, which in turn is mounted for corotation with the shaft means 26a in a manner to be later noted. The intermediate speed drive gear 107 meshes with an intermediate speed driven gear 110 freely rotatable upon shaft means 26b, the gear means 110 being operatively connected through spring clutch means 111 with a highspeed driven gear 112 keyed or otherwise secured as at 113 to the shaft 26b. The high speed gear 112 is driven by a high speed drive gear 114 freely supported upon the shaft 26a and operatively connected to the intermediate speed drive gear 107 by spring clutch means 116.

The clutch housing 109 is positively connected at 108 to the intermediate speed drive gear 107, as was noted. The clutch housing 109 is generally dish-shaped and connected thereto at 117 and axially but not angularly movable with respect to the housing 109 are a plurality of clutch members 118 each spaced along their radially inwardly facing portions by a corresponding plurality of return springs 119. Located in relatively closely spaced relation to one of the sets of the clutch members or friction discs 118 is a radially extending flat portion 120a formed integrally with a friction clutch drive hub 120 keyed as at 121 to the motor shaft 26a. Mounted for axial movement on the hub 120 and between the disc members 118 and the spring members 119 are two additional disc members 118a that transfer power from the hub 120 to the clutch housing 109 when the pneumatic clutch is actuated. Spaced relatively closely to one of the friction discs 118 is a clutch actuating member 122 mounted for axial movement upon the hub member 120. The clutch actuating member 122 is rotated by a hub member 120.

The clutch actuating member 122 is generally angular and has formed thereon a collar portion 122a to provide a seating surface for a thrust bearing means 123 against which acts an axially movable angular piston member 124 backed by a diaphragm means 126. The housing body portion 87 is passaged as at 127 in FIGURE 4 to communicate the diaphragm chamber 126a through the conduit means 46 (FIGURE 3) leading to the solenoid operated valve means 48.

As the diaphragm member 126 expands by the admission of air pressures thereto, the piston member 124 and clutch actuating member 122 are moved axially until the actuating member 122 moves the adjacent set of friction discs or clutch members 118 against clutch discs 118a. Since the hub member is fixedly secured to the shaft 26a and the friction discs 118 are connected to the clutch housing 109, which is in turn positively connected at 108 to the intermediate drive gear 107, the friction discs 118 when engaged by the clutch actuating member 122 and disc 118a rotate to corotate the intermediate drive gear 107, which is, as noted, freely rotatable upon the motor shaft 26a. The intermediate drive gear 107 will thereby drive the intermediate speed driven gear 110, which is also freely rotatable upon its shaft 26b. Since the intermediate speed driven gear 110 is now rotating at a greater rotative speed than the high speed driven gear 112, which is in turn keyed at 113 to its shaft 26b the intermediate speed driven gear 110 will wind up the spring clutch means 111 so that the high speed driven gear 112 is driven from the intermediate speed driven gear 110 through said spring clutch means. Since the high speed driven gear is keyed to the shaft 26b, this shaft will be driven at an intermediate speed.

At this point, the multi-speed output shaft 26b is rotating faster than the low or tumble speed driven gear 96. This overriding action relative movement causes the clutch plate 101 to unwind on the externally threaded tumble drive hub 102. The clutch plate 101 will thereby be threaded to the right away from contact with gear 96 in FIGURE 5, to a stop, and since the clutch plate speed exceeds the speed of the spring member 104 secured to the pin means 106 in the tumble speed driven gear 96, the friction forces exerted by the spring means 104 will produce no clutching action.

Expansion of the diaphragm means 126 and consequent axial movement of the clutch actuating member 122 is dependent upon the supply of sufficient air pressure to the diaphragm from the compressor 49 through the conduit means 50 to the solenoid operated valve means 48 and from said valve means through the conduit means 46 to the opening 127 in the housing portion 87 and to the diaphragm air chamber 126a. In this manner continued operation of the transmission 26 at an intermediate drive speed (low spin speed) is assured.

To accomplish a shift of the transmission from this intermediate drive speed (low spin or extraction speed) to high spin speed, the transmission housing 86 mounts a high speed solenoid designated at 128 in FIGURE 4. The solenoid 128 may comprise a housing 129 attached to the transmission body portion 87 by fastening means 130 and axially slidable within the housing is an armature 131 guided by a yoke member 132. Connected to the armature 131 is a generally triangularly shaped plate member 133 which pivots about the point 134 to raise and lower a rod or pin member 136 which in effect constitutes a right angle extension of armature 131 and depends downwardly through a suitable opening in the housing body portion 87. A pin member 136 is shown diagrammatically in a fragmentary view in FIGURE 5.

The pin member 136 is positioned for engagement with clutch release ring means designated in FIGURE 5 by the numeral 137. The clutch release means is formed with a radial tab or ear 137a threon against which the solenoid extension 136 abuts when the high speed solenoid is deenergized, and radially inwardly of the tab 137a the inner diameter of the clutch release ring 137 is notched as at 13711 to provide a pocket or recess for an axially directed tang 116a on the high speed spring clutch member 116.

By the construction described, when it is desired to shift the transmission to high speed from intermediate speed (low extraction speed), the solenoid operated valve means 48 is de-energized, thereby relieving pressure in the pneumatic clutch in the transmission 26 thus disconnecting the power drive to the drum 24. Immediately thereafter, the high speed solenoid 128 is energized to move the solenoid armature 131 and pivot the plate member 133 about the point 134 which raises the rod-like extension 136 connected at 138 to the plate member. Immediately after the high speed solenoid 128 is energized, the solenoid operated valve means 48 is again energized, thereby gradually pressurizing and actuating the pneumatic clutch means as will be described more fully hereinafter. Raising of the solenoid extension 136 disengages said extension from the tab 137a on the clutch release ring 137, causing the intermediate speed drive gear 107, which is rotating faster than the high speed drive gear 114, to wind up the high speed spring clutch 116 around the hubs of each gear 107 and 114. The high speed drive gear 114 then drives the high speed driven gear 112 which as noted is keyed to the multispeed output shaft 26b at 113. At this time, the high speed driven gear 112 is rotating at a greater speed than the intermediate speed driven gear 110, and accordingly, the intermediate speed spring clutch 111 is unwound.

It may now be observed that after the high speed drive gear 114 is driven the high speed driven gear 112, vibrations of the drum 24 due to unbalanced loads therein will cause intermittent depressions of the valve core stems 74- and 74a of the relief valve 54 to reduce the pressure in the solenoid operated air valve chamber 59. This has the effect of reducing the air pressure input to the pneumatic clutch diaphragm member 126, causing relative slippage between the clutch actuating member 122 and the friction discs 118 and 118a. The drum 24 is thereby maintained at that speed which caused the deflections associated with the unbalanced condition so that a balancing function can be accomplished upon which the drum 24 will continue to accelerate to high speed.

An exemplary form of compressor which may be used in the instant invention is shown in FIGURES 4, 6 and 7, and is designated therein generally by the numeral 49. The compressor comprises a cap portion 139 attached by fastening means 140 to the transmission body portion 88 along the upper surface thereof. Included in the angular cap member 139 is a compressor body portion 141. The body portion 141 is formed interiorly thereof with a piston chamber 142 slidably receiving a piston member generally designated at 143 and comprising a stem portion 144 to which is connected a head portion 146 threadably mounting a cap portion 147 that holds piston member 143 in place against the walls of the chamber 142.

Secured to the compressor housing 141 by fastening means 148 is a spring seat member 149 having a central neck portion 149a mounting a sleeve member 150 providing a piston stem receiving surface. The spring seat member 149 and particularly the neck portion 149a thereof is surrounded by a spring means 151 seating at its opposite end against a spring seat member 152 shown as mounted in encircling relation upon the piston stem 144 and limited in its outward axial travel by retaining means 153.

Carried adjacent one end of the piston stem portion 144 is a cam follower means 98 contoured for engagement with the cam surface 97 on the tumble speed driven gear 96 (FIGURE The cam follower 98 is attached to the piston stem portion 144 at 154, and the transmission body portion 88 is of course apertured to permit the desired reciprocal action of the piston stem portion 144 and cam follower 98.

The compressor housing 141 is formed in the head portion thereof with three passages or openings. A first opening 156 provides an air inlet and may take the shape of a relatively large diameter portion 156a and a connecting reduced diameter portion 156]) terminating at one end in the piston chamber. The relatively large diameter portion 156m of the inlet passage receives therein a spring loaded flat check valve assembly 157 of known 1 31 construction backed on one face thereof by a filter element 158 to prevent the entrance of foreign substances.

A second passage or opening generally designated at 159 in FIGURE 6 provides an air discharge passage and is shaped to include a relatively large diameter portion 159a and a relatively slender portion 15% mounting a nipple member 166 for receiving the conduit means 50 of FIGURE 3. In the relatively larger diameter passage portion 159a there is seated a spring loaded fiat check valve assembly 161, which can be identical to the assembly 157, but located in a reverse position as shown.

The third passage in the compressor cylinder head or body portion 141 is shown in FIGURE 7 and is designated therein by the numeral 162. The passage 162 communicates at one end with atmosphere and at its opposite end with the piston chamber 142, and provides in the structure disclosed a relief valve opening. Within this opening there is received a ball member 163 backed by a spring means 164 seated on its opposite surface against a threaded insert 166. Illustratively, the spring loaded ball check valve 163 opens at approximately 25 p.s.i., which exceeds pressures to be encountered during normal operation of the pneumatic system.

Travel of the cam follower 98 upon the cam surface 97 of the tumble speed driven gear 96 reciprocates the piston head portion 143 in opposite directions, and in its rearward stroke or in movement to the right as shown in FIGURE 6, the spring loaded check valve assembly 157 is forced open to permit the entrance of air to the piston chamber 142 during the suction stroke of the compressor piston. During the compression stroke or when the piston moves to the left in FIGURE 6, the spring loaded check valve assembly 161 opens to direct compressed air through the passage 159 to the conduit means 50 leading to the solenoid operated valve means 48. A tumble speed driven gear 96 upon which the cam surface 97 is formed rotates at constant speed, and there is accordingly assured a constant output of pressurized air to the penumatic clutch of the transmission means 26. In this connection, the spring loaded relief valve is effective to bleed-off eX- cess compressor pressure which builds up therein when the solenoid operated valve means 48 is de-energized.

Electrical control circuitry for sequentially actuating the acceleration control system is illustrated in FIGURE 8 and is connected to the sequential control means 33 (FIGURE 1). As shown, electric power lines 167 and 168 are connected at terminals L and L to a suitable source of electric power and the electric drive motor 25, a timer motor 169, the high sped solenoid 128 and the solenoid operated air valve 48 are connected in parallel to lines 167 and 168. A master switch is connected in line 167 to disconnect all components situated downline thereof. A drive motor switch 170 is connected in series with the motor 25, and a high spin switch 171 is connected in series to the high speed solenoid 128. A pair of switches, namely air valve switch 172 and air valve interrupter switch 173 are connected in mutually parallel relation and in series with the solenoid operated air valve 48.

In operation, the sequential control means 33 is adjusted to a selected wash-dry cycle and actuates the timer motor 169. Among other things, the drive motor switch 170 is closed to energize the motor 25, and at the end of the wash cycle the timer motor 169 sequentially controls the machine through subsequent spin and extraction cycles.

During the wash cycle the air valve switch 172 and the interrupter switch 173 are opened to de-energize the air valve 48, thereby precluding pressure buildup in the pneumatic clutch means of the transmission 26. The high spin switch 171 is also open during the wash. cycle, and the transmission 26 is arranged for low or tumble speed op eration. At the end of the wash cycle, the timer motor 169 acts to close the interrupter switch 173 thereby energizing the solenoid valve 48 which causes the clutch means of the transmission 26, in a manner described here- I I inbefore, to shift to an intermediate or spin speed. After pressurization of the transmission clutch means, of course, deflection of the drum 24 will operate the double acting relief valve 54 (FIGURE 3) to maintain the speed at which the deflection is caused until a balance system counterbalances the unbalanced forces in the drum.

At a predetermined time interval before the termination of the spin cycle, for example, three seconds, the timer mot-or 169 causes the interrupter switch 173 to open, thereby de-energizing the solenoid operated air valve 48 and causing the pressurized air therein to be dumped to atmosphere. Approximately three seconds after the air is v dumped, the high spin switch 171 is closed by the timer motor 169 to energize the high spin solenoid 128, thus shifting the transmission into the high or extraction speed ratio. Simultaneously with or only momentarily after the high spin solenoid 128 is energized the timer motor 169 acts to close the air valve switch 172, thereby re-energizing the solenoid operated air valve 48 and causing the pneumatic clutch means of the transmission 26 to become pressurize-d.

The pneumatic clutch, of course, does not immediately transmit full power from the motor 25 to the drum 24, since slippage occurs therein until full operating pressure is achieved. This slippage is relatively great immediately after the solenoid operated air valve 48 is re-energized and decreases continually thereafter as pressure builds up therein. The air pressure build up, of course, is achieved by the reciprocating compressor 49, which is operatively connected to the constant speed shaft 26a of the transmission 26. With each revolution of the transmission shaft 26a the compressor 49 pumps one stroke, and therefore builds up the pressure in the pneumatic clutch means in increments corresponding to the strokes of the compressor 49.

As the slippage of the pneumatic clutch means decreases with each stroke of the compressor 49, the speed of the drum 24 is gradually increased. The transition of the drum 24 from intermediate speed to high speed is accomplished without instantaneous acceleration and jarring, and for this reason the transition is described as a softshift of the transmission.

The graph of FIGURE 9 illustrates diagrammatically the periods of energization of the drive motor 25, the high spin switch 171, the air valve switch 172 and the interrupter switch 173 as the drum 24 operates through a tumble or wash cycle, and intermediate speed or low spin cycle and a high spin speed or extraction cycle. The abscissa of the graph represent time, and as illustrated the drive motor 25 is energized throughout the entire wash or tumble cycle, the low speed spin cycle and the high spin speed cycle. The interrupter switch 173 is energized upon commencement of the intermediate or low speed spin cycle and remains energized up to approximately three seconds before the termination of this cycle. The air valve switch 172 and the high spin switch 171 are illustrated as being energized simultaneously at the beginning of the high spetled spin cycle and remain energized throughout this eye e.

FIGURES 10 and 11 represent diagrammatically the shifting portion of the cycle showing the air pressure furnished by the compressor 49 and the resultant speed of the drum 24 as the transmission 26 and associated components effect the transition or soft-shift from the intermediate speed of the drum during a low spin cycle to a high speed for the extraction cycle. The abscissa of both graphs represents time. The operation is illustrated diagrammatically in FIGURES 10 and 11 assuming that the drum 24 is in dynamic balance; therefore, air bleed valve 54 will not bleed air during the acceleration of the drum to the maximum speed.

FIGURE 10 illustrates that the discharge pressure of the compressor 49 is at full operating pressure during a spin cycle until approximately three seconds before termination of the spin cycle, such time being represented by the letter 7 legend A in the drawing, after which the air is dumped to 12 atmosphere due to de-energization of the solenoid operated air valve 48. At this time, the pressure of the air drops to O p.s.i., as indicated by the legend B, but begins to build up again incrementally upon re-energization of the valve 48 at the commencement of the extraction cycle as indicated at C. Each stroke of the compressor 49 results in an incremental pressure rise indicated by the legend D, until once again full operating pressure is attained as at B.

As shown in FIGURE 11, the speed of the drum 24 increases gradually from point F upon commencement of the extraction cycle due to gradual incremental build up in pressure in the pneumatic clutch means of the transmission 26 and the available torque of drive motor 25. As such pressure build-up increases, slippage in the pneumatic clutch means decreases, thus gradually transferring the full load of driving the drum 24 to the transmission. The drum 24 will be accelerated to the maximum speed as noted at G at a rate determined by the power output of drive motor 25.

Assuming that the smooth transition or soft-shift feature were not incorporated into the acceleration control system of the present invention, the discharge pressure of the compressor 49 would remain constant at full operating pressure during the transition from intermediate to high speed. Since slippage of the pneumatic clutch means of the transmission 26 would not exist, the full power of the constant speed shaft 26a would be immediately transmitted to the output shaft 26b and correspondingly sudden acceleration of the drum 24 would result, causing a heavy shock load on the components of the transmission. Furthermore, when an off-balance of tank 24 did exist at the time of shifting from low speed spin to high speed spin, the sudden acceleration would cause the drum speed to overshoot the allowable speed permissible to prevent excessive vibration before the air bleed valve 54 would have a chance to relieve the pressure from the pneumatic clutch resulting in excessive vibration of the machine.

The smooth transition or soft-shift feature, in eliminating sudden almost instantaneous acceleration of the drum 24 results in minimum vibration of the machine, reduced wear and long life to the parts as well a other obvious advantages.

Although minor modifications might be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of changing drum speeds in a multiple speed laundry device which includes a driven drum, a multiple speed transmission, a pneumatic clutch in said transmission, a motor powering said drum through said transmission, and a pneumatic compressor supplying air to said clutch, said method comprising:

rotating said drum at a low extraction speed to effect spinning of fabrics within said drum,

de-energizing said pneumatic clutch to interrupt the power supplied from said motor to said drum, changing said transmission to a higher speed ratio while said clutch is disengaged,

re-energizing said pneumatic clutch, and

gradually increasing pneumatic pressure to gradually transfer power to said high speed ratio.

2. The method of operating a centrifuging apparatus which includes the steps of operating an electric drive motor at a constant rotational speed, connecting in driven relation therewith a rotatable drum through a multiple speed changing transmission by means of a pneumatically operated clutch,

driving the drum at a first speed ratio of the transmission sufficiently fast that the contents of the drum will be carried at the periphery of the drum,

actuating the clutch to disengage the connection between the drum and the motor,

while so disengaged changing the transmission to a second higher speed ratio,

re-engaging the clutch,

and gradually increasing pneumatic pressure in incremental steps to transfer the power to said second higher speed ratio gradually.

'3. Means for changing drum speeds in a multiple speed laundry device of the type which includes a driven drum, a multiple speed transmission, a fluid actuated clutch in said transmission, a motor powering said drum through said transmission and a fluid pump for supplying fluid to said clutch to actuate said clutch, said means comprising,

means for rotating said drum at one speed at a given speed ratio of said transmission,

means for interrupting the supply of fluid to said clutch to deactivate said clutch for interrupting the power transmitted from said motor to said drum, means for changing said transmission to a diflerent speed ratio while said fluid supply is interrupted, and

means for i e-establishing the supply of fluid to said clutch to cause said clutch to gradually re-institute the transmitting of power from said motor to said drum.

4. Means for changing drum speeds in a multiple speed laundry device of the type which includes a driven drum, a multiple speed transmission, a pressurized fluid operated clutch in said transmission, a motor powering said drum through said transmission and a fluid compressor supplying pressurized fluid to said clutch to activate said clutch, said means comprising,

first means selectively operative to rotate said drum at one speed at a given speed ratio of said transmission, second means selectively operative to reduce the pressure of said fluid being supplied to said clutch to deactivate said clutch and to interrupt the transmitting of power from said motor to said drum, third means selectively operative to change said transmission to a different speed ratio while the pressure of said fluid is reduced,

fourth means selectively operative to eflect a gradual increase in the pressure of said fluid to gradually reinstitute the transmission of power from said motor to said drum, and means for operating said first, said second, said third and said fourth means in sequence.

5. The method of changing drum speeds in a multiple speed laundry device which includes a driven drum, a multiple speed transmission, a pneumatic clutch in Said transmission, a motor powering said drum through said transmission and a pneumatic compressor supplying pressurized air to said clutch, said method comprising,

rotating said drum at one speed at a given speed ratio of said transmission, operating said compressor at a given speed, reducing the pressure of the air being supplied to said clutch to interrupt power transmitted from said motor to said drum,

maintaining the operative said given speed while duced,

changing the transmission to a diiferent speed ratio, and

gradually increasing the pressure of said air being supplied to said clutch to gradually change the speed of said drum corresponding to the change in speed ratio of said transmission.

6. The method of changing drum speeds in a multiple speed laundry device which includes a driven drum, a multiple speed transmission, a pneumatic clutch in said transmission, a motor powering said drum through said transmission, a pneumatic compressor for supplying air pressure to said clutch to activate said clutch, conduit means interconnecting said compressor and said clutch speed of said compressor at the pressure of said air is re and an electric solenoid valve in said conduit for releasing said air pressure in said clutch when said valve is deenergized, which includes the steps of,

rotating the drum at a given speed corresponding to a given speed ratio of said transmission, de-energizing said solenoid valve to release the air pressure in said clutch to deactivate said clutch for interrupting power from said motor to said drum, changing the speed ratio of said transmission, re-energizing said solenoid, and gradually increasing the pressure of said air in said clutch to gradually reactivate said clutch for gradually reinstituting power transmission from said motor to said drum.

7. The method of changing drum speeds in a multiple speed laundry device which includes a driven drum, a multiple speed transmission, a pressure activated pneumatic clutch in said transmission for interrupting power from said motor to said drum, a reciprocating compressor for supplying pressurized air to said clutch and an electric solenoid valve for releasing the air pressure in said clutch for deactivating said clutch, including the steps of rotating the drum at a given low speed corresponding to a given speed ratio of said transmission, de-energizing said solenoid valve to release the air pressure in the clutch to deactivate said clutch for interrupting power from said motor to said drum, changing said transmission to a higher speed ratio, re-ene-rgizing said solenoid valve to .allow air pressure to build up in said clutch, and

increment-ally increasing the air pressure in said clutch in accordance with the strokes of said compressor to gradually reactivate said clutch and gradually increase the speed of said drum to correspond to the higher speed ratio of said transmission.

8. Means for changing drum speeds in a multiple speed laundry device of the type which includes a rotatably driven drum, a multiple speed transmission, a fluid actuated clutch in said transmission, a motor powering said drum through said transmission, a fluid pump for supplying fluid to said clutch to actuate said clutch and a programmed sequential controller for controlling said laundry device through sequence of operations, said means comprising,

valve means operated by said sequential controller to supply fluid to said clutch to provide rotation of said drum at a first speed,

said valve means operated by said sequential controller to interrupt the supply of fluid to said clutch for interrupting the power transmitted from said motor to said drum, speed changing means operated by said sequential controller for changing the speed ratio of said transmis sion to a second higher speed while said fluid supply is interrupted,

said sequential controller having control elements operating said valve means to supply fluid to said fluid clutch after said speed changing means has been operated to cause said clutch to gradually reinstitute the transmitting of power from said motor to said drum.

9. Means for changing drum speeds in a multiple laundry device of the type which includes a rotatable drum, a multiple speed transmission, a pressurized fluid actuated clutch in said transmission, a motor connected to said drum through said transmission, a fluid pump, conduit means communicating said pump and said clutch, and a programmed sequential controller to control said laundry device through a sequence of operations, said means comprising,

electrically operated valve means mounted in said conduit means to interrupt the supply of pressurized fluid to said clutch to deactivate said clutch,

15 15 electrically operated speed changing means connected to effect activation of said clutch after the speed to said transmission and operative to change the ratio has been changed.

speed ratio of said transmission References Cited said sequential controller comprising control circuit means operatively connected to said valve 5 UNITED STATES PATENTS means and to said speed changing means for 3,148,144 9/1964 Brenner et al. 2l0144 sequential operation thereof to effect deactivation of said clutch before the speed ratio of said REUBEN FRIEDMAN Pr'mary Exammer' transmission is changed, and J. DECESARE, Assistant Examiner. 

1. THE METHOD OF CHANGING DRUM SPEEDS IN A MULTIPLE SPEED LAUNDRY DEVICE WHICH INCLUDES A DRIVEN DRUM, A MULTIPLE SPEED TRANSMISSION, A PNEUMATIC CLUTCH IN SAID TRANSMISSION, A MOTOR POWERING SAID DRUM THROUGH SAID TRANSMISSION, AND A PNEUMATIC COMPRESSOR SUPPLING AIR TO SAID CLUTCH, SAID METHOD COMPRISING: ROTATING SAID DRUM AT A LOW EXTRACTION SPEED TO EFFECT SPINNING OF FABRICS WITHIN SAID DRUM, DE-ENERGIZING SAID PNEUMATIC CLUTCH TO INTERRUPT THE POWER SUPPLIED FROM SAID MOTOR TO SAID DRUM, CHANGING SAID TRANSMISSION TO A HIGHER SPEED RATIO WHILE SAID CLUTCH IS DISENGAGED, RE-ENERGIZING SAID PNEUMATIC CLUTCH, AND 